Marie Halff, emeritus museum trustee and trustee of the foundation, announced the gift at an event in June honoring director William Chiego, who is retiring in September after 25 years at the head of the institution.

“It’s very meaningful because endowment gifts are very often the hardest to raise and it’s really significant because it makes a real difference to our ability to acquire American works of art in the future,” Chiego said. “That’s an area of the collection that is bound to keep growing and an area where we’ve been very active during my tenure. So this will help in the future to keep that part of the collection growing.”